Alberto Salazar, Farah’s coach, told The Oregonian that Farah felt severe stomach pains while training in Park City, Utah last week. He was hospitalized and underwent tests, but no serious ailment was discovered.

He has flown to the UK for further testing with the British Athletics medical team.

Farah released a statement apologizing:

Sorry to everyone in Scotland but I won’t be able to make it there this week. I hope to resume training in the next few days and aim to run in the London Anniversary Games on July 20 and then the Commonwealth Games the following week.

The reigning Olympic champion in the 5000m and 10000m distances, Farah tried the marathon distance in London in April, finishing eighth.